A milking machine

Abstract: A milking machine for milking animals, such as cows, which is provided with one or more filtration devices (8) for filtering milk. Such a filtration device (8) is provided with one or more filters (9, 10) and also with change-over means (15 to 18) to direct a flow of milk automatically through a filter (9, 10) to be cleaned regularly. This cleaning is effected by means of a cleaning liquid, which is led through the filter (9, 10) in a direction which is opposite to that in which the milk passes through the filter (9, 10). When a given filter (9; 10) is being cleaned, the milk flows through an other filter (10; 9).

Description: The present invention relates to a milking machine according to the preamble of claim 1. Such a filtering device for liquids in general is disclosed in US-A-4 636 306. Another filtration device is disclosed in DD-A-221625. This device comprises a disc with filter segments. Each time a cow is milked, a filter segment is used to filter the milk by moving the disc in a different position. After milking the entire herd the filter disc is removed, cleaned and disinfected. The filtration device as disclosed in DD-A-221625 has the drawback that it has to be exchanged manually. This is time-consuming and inconvenient. Also, the filter exchange interrupts the milking process. This is particularly inconvenient in systems of continuous milking, such as robotic milking systems. NL-A-9300143 discloses a filtration device which enables exchanging the filters without interrupting the milking process. This device has the drawback that the filters need to be replaced and cleaned manually which is again time-consuming, expensive and inconvenient. To enable an uninterrupted purification of the milk, a filtration device according to the invention is provided with the features of claim 1. In this way the flow of milk from animals milked in succession can be purified by filtration by means of a filter cleaned regularly without requiring that additional time is allotted for filter cleaning. When the milk is led through a first filter, a second filter can be cleaned. In principle, it will be sufficient to provide two filters in the filtration device, so that, when the milk is passed through one filter, the other filter is cleaned and, after this other filter has been cleaned and a certain number of cows has been milked subsequently, the milk is passed through the cleaned filter, whereas then the first-mentioned filter is being cleaned. For this purpose there are provided automatically operated change-over means to direct at the same time the milk flow in one direction through a first filter and a cleaning liquid in the opposite direction through a second filter. The change-over means may be made up of multi-way valves, particularly computer-controlled three-way valves, by which in a first position milk, and in a second position a cleaning liquid is allowed to pass through a filter. The filters may be of tubular design and, extending upwardly, they may be arranged in parallel. The cleaning liquid can be hot water, which is fed pulsatingly through a relevant filter. A filtration device in which a flow of milk is automatically redirected from a first filter to a second one, with the unused filter(s) being cleaned, can be applied advantageously in an automatic milking machine. The milking machine can then be provided with a milking robot for connecting teat cups automatically to the teats of an animal present in a milking parlour and for subsequently milking this animal automatically, whilst the milk obtained is routed through an automatically operative filtration device and is purified there. Then, the filtration device is preferably disposed near the milking parlour, whilst the filtration device can be included in that part of the milk line system which extends from the teat cups to a milk meter being part of the milking machine. The invention will now be further explained with reference to an exemplary embodiment of the invention as represented in the following drawings, wherein: Figure 1 shows a milking parlour and a schematically represented part of a milking machine in accordance with the invention; Figure 2 shows a filtration device according to the invention such as it is applied in the milking machine part schematically represented in Figure 1, and Figure 3 is a plan view of the filtration device in Figure 2. Figure 1 shows a schematic representation of a milking parlour 1, in which there is a cow 2. As is usual, the milking parlour is constituted of a fencing 3, in which there are provided an entrance and an exit for the cow. At the front side of the milking parlour there is an automatic feeder, of which the feed trough 4 is schematically represented. On the lowermost beam of the fencing 3 on the longitudinal side of the milking parlour 1, as shown in Figure 1, there is provided a milking robot 5. Though not further indicated in the drawings, the milking robot 5 has all degrees of freedom necessary to put the teat cups 6 disposed near the end of a robot arm 7 of the milking robot 5 into a position underneath the teats of the cow 2 and to connect the teat cups 6 to the teats of the cow 2. The milking machine is provided with a milking robot 5 for automatically connecting teat cups to the teats of an animal present in the milking parlour 1 and for subsequently automatically milking this animal. The milk obtained through the individual teat cups can be directed to an individual filtration device 8, where the milk is purified by filtration. Naturally, it is also feasible to direct the milk obtained by using all four of the teat cups 6, through a single line, to a single filtration device 8 to filter the total flow of milk from the cow. The milking machine can comprise a single filtration device as well as a plurality of filtration devices for filtering milk. The filtration device is placed near the milking parlour 1, in Figure 1 alongside of this milking parlour. There the filtration device is included in that part of the milk line system which is between the teat cups and the further milking equipment, such as a milk meter or the milk tank in which the milk obtained is collected. The filtration device 8 is depicted in more detail in Figures 2 and 3. The filtration device 8 comprises two filters 9 and 10. Extending in an upward direction, these filters are disposed in parallel, and either one is composed of a tubular outer jacket 11 in which a filter element 12 extends virtually over the full length. At the bottom of the outer jacket 11 there is provided an opening 13 in each filter, while there is provided an opening 14 at the top of the filter element which pierces the outer jacket 11 at the top of the filter. A liquid, particularly milk, can be put into the filter element 12 through the opening 14, with the milk flowing into the space between the filter element 12 and the outer jacket 11, via the wall of the filter element 12, and being carried off from there via the opening 13. By supplying milk through the opening 14 and carrying it off through the opening 13, any contaminants included in the milk are left on the interior side of the filter element 12. The filter can be cleaned by putting a cleaning liquid into the space between the outer jacket 11 and the filter element 12 through the opening 13. This cleaning liquid enters the space in the filter element 12 through the wall of the filter element 12 and it is carried off through opening 14. By forcing a cleaning liquid in this direction through the filter, the particles which had accumulated in the interior space of the filter element 12 are washed away and removed from the filter. The filters 9 and 10 in Figure 2 can be passed through by the milk from the top downwards, whereas for the purpose of cleaning, a cleaning liquid is fed from the bottom upwards through the filter. The direction of flow of the cleaning liquid is consequently opposite to that of the liquid to be purified, milk in this case. To be used as a cleaning liquid is, for instance, hot water to which special cleaning agents have been added, if required. Furthermore, the cleaning liquid can be pulsatingly fed through the filter, which increases the cleaning effect. The openings 13 and 14 of the filters 9 and 10 are connected to automatically operated change-over means 15 - 18 in the form of multi-way valves, three-way valves in this case. In a first position, the three-way valves 15 - 18 enable milk to pass through the filters and in a second position cleaning liquid. Further, a milk inlet line 19 and a cleaning-liquid outlet line 20 are connected to the three-way valves 15 and 17, while a milk outlet line 21 and a cleaning liquid inlet line 22 are connected to the three-way valves 16 and 18. In the position of the three-way valves as shown in Figure 2, milk is discharged by the line 21 via the three-way valve 15, the filter 9 and the three-way valve 16, whereas at the same time a cleaning liquid is fed through the line 22, the three-way valve 18, the filter 10 and the three-way valve 17 into the line 20 for discharge. By changing over the three-way valves 15 - 18, the milk can be led through the filter 10 and the cleaning liquid through the filter 9. The change-over of the three-way valve is under the control of a computer, not further detailed here, which computer has otherwise control of the whole milking machine including the milking robot and accessory devices. The computer can be programmed such that the change-over of the three-way valves takes place after a predetermined number of cows has been milked. Particularly, the filtration device can be changed over each time when a single cow has been milked, so that the milk from each cow is invariably led through a cleaned filter. The invention is by no means limited to the embodiment reflected here, but it also relates to all kinds of feasible variants and modifications thereof, of course, falling within the scope of protection of the claims following hereinafter. In particular, there can be provided more than two filters in a filtration device and, as stated before, a plurality of filtration devices can be installed.

Claims: A milking machine for milking animals, such as cows, comprising one or more filtration devices (8), the filtration device being provided with at least two filters (9, 10), and with connections to pass alternately milk in a first direction through a filter and a cleaning liquid through this filter in a second direction, opposite to the first direction, and wherein, when the connections are in position to pass milk through one filter a cleaning liquid may pass through another filter, characterized in that there are provided automatically operated change-over means (15 to 18) to provide for cleaning of one filter when milk is passed through the other filter, and for passing, after the first filter has been cleaned and a predetermined number of cows has been milked subsequently, the milk through the cleaned filter, whereas then the said other filter is being cleaned. A milking machine according to claim 1, characterized in that the filtration device (8) comprises two filters (9, 10). A milking machine according to any one of the preceding claims, characterized in that there are provided automatically operated change-over means (15 to 18) to direct at the same time the milk flow in one direction through a first filter (9; 10) and a cleaning liquid in the opposite direction through a second filter (10; 9). A milking machine according to any one of the preceding claims, characterized in that the change-over means (15 to 18) are constituted by multi-way valves. A milking machine according to claim 4, characterized in that the multi-way valves (15 to 18) comprise computer-controlled three-way valves, which in a first position allow milk to pass through a filter (9, 10) and in a second position a cleaning liquid. A milking machine according to any one of the preceding claims, characterized in that a filter (9, 10) is of tubular design. A milking machine according to claim 6, characterized in that the filters (9, 10) extending upwardly are arranged in parallel. A milking machine according to any one of the preceding claims, characterized in that the cleaning liquid is hot water, which is fed pulsatingly through a filter (9, 10). A milking machine according to any one of the preceding claims, characterized in that it is provided with a milking robot (5) for connecting teat cups (6) automatically to the teats of an animal present in a milking parlour (1) and for subsequently milking this animal automatically, whilst the milk obtained is routed through an automatically cleaned filtration device (8) and is purified there. A milking machine according to claim 9, characterized in that the filtration device (8) is disposed near the milking parlour (1). A milking machine according to claim 9 or 10, characterized in that the filtration device (8) is included in the milk line system between the teat cups (6) and a milk meter being part of the milking machine.

Inventors: VAN DER LELY CORNELIS, VAN DER LELY, CORNELIS
Applicants: MAASLAND NV, MAASLAND N.V.
Application year: 1994
Main classification: A01J7
IPC codes: A01J7, A01J11